She was also considered at one time for the role of Nova in the original Planet of the Apes film. In 1967 Pettyjohn and Michael J. Pollard appeared together in an episode of The Girl from U.N.C.L.E ("The U.N.C.L.E. Samurai Affair"). She also appeared alongside Seymour Cassel and Roger C. Carmel in an episode of Batman the same year.

Angelique was a natural for erotic photography; she even appeared in three hardcore adult films, in 1982. Pictures of her, topless, wearing the Shahna costume and drill thrall harness and collar exist. She was also sometimes credited as Heaven St. John or as Angel St. John for her adult films.

Her appearance in Star Trek initially did nothing to further her acting career, as she was only cast in a series of increasingly worse produced "B-movies", typically made for the drive-ins and the exploitation circuit, such as Hell's Belles (1969), The Curious Female (1970), and Bordello (1974), and which eventually resulted in her appearance in the three hardcore adult movies, the low point in her career, aggravated by alcohol and drug abuse, living in a cabin in the backwoods of Virginia at one point.

Still, in a curious turn of events, Pettyjohn's fortunes took a turn, imperceptibly at first, for the better from 1979 onward, as the Star Trek convention circuit gathered steam, bolstered on by the release of Star Trek: The Motion Picture. As "The Gamesters of Triskelion" episode was a fan favorite, Pettyjohn found herself in increasingly high demand as a Star Trek convention guest of honor, and since then she vigorously worked the circuit, eventually enabling her to make a living from it, until her last appearance on the circuit in 1989. In the process, she also managed to overcome her bouts of alcohol and drug abuse.

Her new-found fame on the convention circuit attracted the attention of independent movie makers ("Indies"), which led to her roles in indie features such as Repo Man (1984), Biohazard (1985), and The Wizard of Speed and Time (1988). In 1989, she was offered employment as an exotic (note: not erotic) dancer on the Las Vegas casino circuit.